1. Field of the Invention
The disclosures herein generally relate to printer modules, and particularly relate to a printer module for use in a clamshell-type printer apparatus wherein the printer module includes two modules that are combined to form a cutter unit having a movable blade and a fixed blade facing each other.
2. Description of the Related Art
A clamshell-type printer apparatus has an openable lid and a main body having respective modules attached thereto, which are joined together upon the rotational closing motion of the openable lid.
A description will be given of a cutter unit having a movable blade and a fixed blade facing each other in a printer module for use in the clamshell-type printer apparatus.
FIG. 1 is a drawing illustrating a typical cutter apparatus 11 of a thermal printer module 10 having a movable blade module 15 and a fixed blade module 12 joined together. X1-X2 represents the width direction of the thermal printer module 10. Y1-Y2 represents a direction along which the fixed blade module 12 and the movable blade module 15 are arranged. Z1-Z2 represents the height direction of the thermal printer module 10.
The fixed blade module 12 has a fixed blade 13, and the movable blade module 15 has a movable blade 16 that is movable in the Y1-Y2 direction.
In the cutter apparatus 11, the edge of the movable blade 16 is in contact with the edge of the fixed blade 13 on the Z1 side thereof when the movable blade module 15 is joined to the fixed blade module 12. Movement of the movable blade 16 in the Y2 direction serves to cut a sheet by functioning like a scissors.
In FIG. 2B, the movable blade 16 is placed at a desirable angle θ0 relative to the fixed blade 13.
When the angle is θ1 (>θ0) as shown in FIG. 2A, the cutter apparatus has a short lifetime due to the high abrasion of the fixed blade 13 and the movable blade 16.
Conversely, when the angle is θ2 (<θ0) as shown in FIG. 2C, the plunging power of the movable blade 16 into a sheet is weak, thereby providing a blunt cutter.
FIGS. 3A through 3C are drawings illustrating a related-art thermal printer module 20. FIGS. 4A through 4C are drawings showing the way a cutter unit 21 is formed in the thermal printer module 20. FIGS. 5A and 5B are drawings illustrating a thermal printer apparatus 40 in which the thermal printer module 20 is embedded. FIG. 3A, FIG. 4A, and FIG. 5A correspond to each other, and FIG. 3B and FIG. 4B correspond to each other. Further, FIG. 3C, FIG. 4C, and FIG. 5B correspond to each other.
A fixed blade module 25 includes a fixed blade 26, a hook 28, and a thermal head 29 as shown in FIG. 3A. The fixed blade 26 is pushed upward by a plate spring 27 to assume a slanted position as shown in FIG. 4A.
A movable blade module 30 includes a movable blade 31 and a platen roller 32 as shown in FIG. 3A. The platen roller 32 has platen roller shaft parts 33 on its opposite ends.
The movable blade module 30 is brought closer to the fixed blade module 25 as indicated by an arrow in FIG. 3A, and, then, the platen roller shaft parts 33 engage the hook 28. As illustrated in FIG. 3B, the movable blade module 30 is joined to the fixed blade module 25 to form the thermal printer module 20. O1 indicates a joint point at which the platen roller shaft parts 33 engage the hook 28.
The platen roller 32 is pressed against the thermal head 29 to form a print unit 22. Further, the edge of the movable blade 31 is placed in contact with the edge of the fixed blade 26 on the Z1 side thereof, thereby forming the cutter unit 21.
The urging force of the plate spring 27 rotationally urges the movable blade module 30 around the center O1 in the counterclockwise direction indicated by an arrow CC. The fixed blade module 25 is rotationally urged in the clockwise direction as indicated by an arrow C.
The fixed blade module 25 and the movable blade module 30 are not specifically configured to regulate the above-noted rotational movement. The movable blade module 30 exhibits rotational movement until some portion thereof comes in contact with some portion of the fixed blade module 25, thereby settling in the state as shown in FIG. 3B. In this state, the movable blade 31 and fixed blade 26 of the cutter unit 21 form a chevron shape as shown in FIG. 4B. The angle between the movable blade 31 and the fixed blade 26 is θ10, which is significantly larger than θ0.
It should be noted that the thermal printer module 20 is placed in such a state that the movable blade module 30 can be rotationally moved in the direction indicated by the arrow C relative to the fixed blade module 25 by bending the plate spring 27.
As illustrated in FIG. 5B, the related-art thermal printer apparatus 40 has such a configuration that the thermal printer module 20 is mounted in an apparatus main body 41. The apparatus main body 41 includes a case 42 and a rotationally openable lid 50. The case 42 is a molded synthetic resin component.
As illustrated in FIG. 5A, the case 42 includes a paper roll container part 43 for storing a paper roll 80 and a mounting platform part 44 on which the fixed blade module 25 is mounted. Further, the case 42 includes a hinge bracket part 45 at an end of the paper roll container part 43.
The rotationally openable lid 50 includes a lid main body 51, a hinge bracket part 52, and a mounting platform part 53. The lid main body 51 has such a size as to cover the paper roll container part 43. The hinge bracket part 52 is provided at the base end of the lid main body 51. The mounting platform part 53 serves as a platform on which the movable blade module 30 is mounted.
The hinge bracket part 52 of the rotationally openable lid 50 is supported by the hinge bracket part 45 via a shaft 46. The rotationally openable lid 50 is opened and closed by rotating about the shaft 46.
The fixed blade module 25 is fixed to the mounting platform part 44 of the case 42 by threadable mounting. The fixed blade module 30 is fixed to the mounting platform part 53 of the rotationally openable lid 50 by threadable mounting.
The position of the mounting platform part 44 relative to the shaft 46 (as determined by measurement y10 and measurement z10) and the position of the mounting platform part 53 relative to the shaft 46 (as determined by measurement y11 and measurement z11) are arranged to provide the positional relationship as illustrated in FIG. 5B. Namely, when the rotationally openable lid 50 is closed by rotating clockwise, the movable blade module 30 is joined to the fixed blade module 25 in the positional relationship as illustrated in FIG. 3C With this positional relationship, the angle of the movable blade 31 relative to the fixed blade 26 in the cutter unit 21 is made equal to the optimum angle θ0 as illustrated in FIG. 4C.
Namely, the thermal printer apparatus 40 is configured such that the apparatus main body 41 controls an angle between the movable blade 31 and the fixed blade 26 in the cutter unit 21 of the thermal printer module 20.
As described above, the thermal printer apparatus 40 is configured such that the apparatus main body 41 controls an angle between the movable blade 31 and the fixed blade 26 in the cutter unit 21 of the thermal printer module 20. The above-noted angle of the cutter unit 21 is thus affected by the dimension errors of the case 42 and the rotationally openable lid 50, the positional error of the fixed blade module 25 mounted on the mounting platform part 44, the positional error of the movable blade module 30 mounted on the mounting platform part 53, etc. In some cases, the angle between the movable blade 31 and the fixed blade 26 in the cutter unit 21 may be set larger than or smaller than the desirable angle. In such a case, the short lifetime or blunt cutting of the cutter unit 21 becomes a problem as previously described.
The size of the thermal printer apparatus 40 has been reduced over the years, resulting in the length of the rotationally openable lid 50 being relatively short, i.e., the measurement y11 being relatively short. In such a case, the effect of the dimension errors and positional errors noted above on the angle of the cutter unit 21 becomes larger than in the case in which the length of the rotationally openable lid 50 is long.
Further, the movable blade module 30 is securely fixed to the mounting platform part 53. In order to ensure that the movable blade module 30 is smoothly joined to the fixed blade module 25, thus, the part in which the shaft 46 of the rotationally openable lid 50 is fit provides a loose fit to allow some movement of the shaft 46. There is thus a risk of having loose movements when the rotationally openable lid 50 is open.
Accordingly, it is preferable to provide a printer module and printer apparatus that eliminate the problems described above.    [Patent Document 1] Japanese Patent Application Publication No. 2005-081774